What brings the membrane potential to threshold?
Correct answer: A. Influx of sodium ions across the postsynaptic membrane
- A. Influx of sodium ions across the postsynaptic membrane
- B. Outflow of sodium ions across the postsynaptic membrane
- C. Outflow of calcium ions across the postsynaptic membrane
- D. Influx of potassium ions across the postsynaptic membrane
Explanation
When an excitatory neurotransmitter binds to its receptor on the postsynaptic neuron, it triggers an influx of sodium ions (Na+) across the postsynaptic membrane. This influx of positively charged ions depolarizes the membrane, bringing the membrane potential closer to threshold. If the membrane potential reaches threshold (typically around -55mV), an action potential is generated.
Last updated
About Coordination and Control
Coordination depends on receptors, neurons, synapses and nerve impulses, with reflex actions traced through the reflex arc and the roles of major brain regions. Chemical coordination covers endocrine glands and hormones, including how hormones regulate growth, metabolism, reproduction and internal balance, unlike rapid nervous control.
Practise Coordination and Control
1,687 free Coordination and Control MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A 30 years old male complains of being over weight, sluggish in nature, hair loss, dry skin and intolerance of cold, he is suffering from:
A band of axons between two hemispheres is termed as:
A branch form the body of a neuron, which usually carries information away from its cell body, is:
A branch from the body of a neuron, which usually receives information:
A bundle of axons or dendrites bounded by connective tissue inside the CNS is: